ProgramNode(0...7)(
  [],
  StatementsNode(0...7)(
    [CallNode(0...7)(
       CallNode(0...1)(nil, nil, (0...1), nil, nil, nil, nil, 0, "a"),
       (1...2),
       (2...7),
       nil,
       nil,
       nil,
       nil,
       0,
       "happy"
     )]
  )
)
